Five dilemmas inherent in emergency response are presented and discussed from a public mental health perspective in reference to the IASC Guidelines on Mental Health and Psychosocial Support in Emergency Settings. These are: (1) Who should take the lead in the planning and implementation of the guidelines? (2) At what level are the guidelines to be used? 3) What evidence do we have for the usefulness of the guidelines? 4) What are the costs for the proposed interventions, and how are the activities to be financed? (5) What is the place of specific mental health and psychosocial support within the interventions?